Drift Evaluation of a Quadrotor Unmanned Aerial Vehicle (UAV) Sprayer: Effect of Liquid Pressure and Wind Speed on Drift Potential Based on Wind Tunnel Test

Background: Unmanned Aerial Vehicles (UAVs) applied to agricultural plant protection is widely used, and the field of operation expanding due their high efficiency pesticide application reduction. However, work on drift lags behind development UAV spraying device. Methods: We compared spray potential at four liquid pressures 2, 3, 4, 5 bar ejected from hydraulic nozzles mounted a test platform exposed different wind speeds 6 m/s produced by tunnel. The combination tunnel was used obtain strict conditions. droplet size distribution under measured laser diffraction instrument. Results: Increasing pressure leads smaller volume diameters fine droplets less than 100 µm. deposition in area elevated most sampling locations setting higher faster speed. ratios were all flow three after adjustment pressures. For samples within short distance (2–8 m), with rotor motor off more an order magnitude that 3 bar. Conclusions: In this study, speed had significant effect drift, significantly inhibited large number drifting further.